Christian is now a post doc

[bibshow file =js.bib]

Congratulations to Christian who recently managed to defend his PhD thesis succesfully! Lots of thanks go to Urbana Champagne, Illinois, to André Schleife who supported Christians very advanced and elaborous optics simulations a lot. The thesis can be found online and parts of it were already published [bibcite key=wagner2016empirical,kolchuzhin2014system,wagner2012dft,wagner2012nanomechanics]. Continue reading

Improved recursive Green’s function formalism

[bibshow file =js.bib]

In his most recent publication “Improved recursive Green’s function formalism for quasi one-dimensional systems with realistic defects” Fabian shows a significant speedup of his  recursive Green’s function formalism [bibcite key=teichert2017improved]. Based on that, the conductivity of carbon nano tubes can be computed much faster. This allows to compute tubes of realistic size with a huge number of defects.  Continue reading

Atomic layer deposition on carbon nano tubes

[bibshow file =js.bib]

Chemical functionalization of carbon nano tubes is a very hot topic as it is considered now as one of the key step for the fabrication of tube based electronic devices. By nature, carbon nanotubes are chemically quite inert and thus defects are required as seed for the growth of functional layers. In a recent simulation study Anja shows now, how the first steps of aluminum oxide atomic layer deposition can be performed on typical CNT defects [bibcite key=forster2017ab]. Continue reading

Empirical transport model of strained CNT transistors used for sensor applications

[bibshow file =js.bib]

cnt_psCarbon nanotubes show electronic properties which are remarkably sensitive to mechanical strain. Thus, CNTs are expected to be promising candidates for nano scale strain sensors.  Even more, they are discussed as a key component of future nano-opto-electro-mechanical systems (NOEMS).

Consequently, a comprehensive model for strained CNT transistors was recently published by Christian [bibcite key=wagner2016empirical]. Continue reading

Surface chemistry of copper metal and copper oxide atomic layer deposition

Cu_acac_2[bibshow file =js.bib]

In a recent paper in Physical chemistry chemical Physis we study the mechanisms for atomic layer deposition using the Cu(acac)2 precursor [bibcite key=hu2015surface]. By first-principles calculations and reactive molecular dynamics simulations we show that Cu(acac)2 chemisorbs on the hollow site of the Cu(110) surface and decomposes easily into a Cu atom and the acac-ligands. Continue reading

Modeling the in situ repair of ULK dielectrics

repair[bibshow file =js.bib]

Ultra low-k dielectrics are one of the key components  which allow for further shrinking of the the interconnect system used in todays semiconductor technology. During manufacturing steps such as trench etching the ULK material is degraded and some repair chemistry is required to restore its k-value. In a recent paper which appeared in Journal of Vacuum Science and technology  [bibcite key=forster2015theoretical] Anja now modeled elementary steps of such an in-situ repair approach by using DFT calculations.   Continue reading

Christian @USA

Christian now went to US for a few months. He will study advanced electronic structure calculations in André Schleife’s group at the university of Illinois at Urbana-Champaign. Christian will use the methods  to calculate the optical properties of CNTs which will finally complement his PhD. André, who initially comes from Chemnitz as well, is a recognized expert in this field. We wish Christian a good and succesfull stay and thank André for his support.

Watch the Christian @USA blog to be up to date!

Strong localization in defective carbon nanotubes: a recursive Greenʼs function study

MV[bibshow file =js.bib]

The paper by Fabian appeared recently in New Journal of Physics [bibcite key=teichert2014strong]. Based on a very efficient linearly scaling algorithm Fabian was able to calculate the electron transport in defective CNTs of realistic size, i.e. up to a length of microns. Continue reading

Metallic carbon nanotubes with metal contacts: electronic structure and transport

contact[bibshow file =js.bib]

Andreas managed to publish the main results of his PhD-thesis in a nanotechnology paper.[bibcite key=zienert2014metallic] The paper deals with the contact properties of metallic carbon nanotubes to several metals, which are of relevance for future carbon electronics. Continue reading